← Back to Patent Explorer
US5817389A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical disk

Assignee: Sony Corp
•
Filing: 1996-10-29
•
Granted: 1998-10-06
•
Expires: 2016-10-29
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract It is an object of the present invention to increase an amount of information recorded on an optical disk having at least two information recording layers. An optical disk having a plurality of information recording layers according to the present invention includes a transparent substrate, a transparent layer and at least two information recording layers formed on the transparent substrate. The information recording layers are provided so as to sandwich the transparent layer. At least one of the information recording layers has a transmittance varying layer. The transmittance varying layer is made of a material whose transmittance is changed at a predetermined temperature as a threshold value. The transmittance varying layer is made of a phase change material. The threshold value is within the temperature range from 700 DEG to 500 DEG . Crystallization speed of the transmittance varying layer is equal to or slower than 500 ns.

Inventors

  • 👤 Masumi Ono

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 20:46
CPC Classifications
B; B82; B82Y; B82Y10/00; G; G11; G11B; G11B7/00; G11B7/24; G11B7/2403; G11B7/24035; G11B7/24038; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S430/00; Y10S430/146; Y10T; Y10T428/00; Y10T428/21

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 46 words
An optical disk comprising in this order: a transparent substrate; a first recording layer on said substrate; a transparent layer on said first recording layer; and a second recording layer on said transparent layer, said second recording comprising a transmittance varying layer and a reflective layer.
Claim 2
Dependent Claim 46 words
An optical disk comprising in this order: a transparent substrate; a first recording layer on said substrate; a transparent layer on said first recording layer; and a second recording layer on said transparent layer, said second recording comprising a transmittance varying layer and a reflective layer.
Claim 3
Dependent Claim 28 words
An optical disk according to claim 1, wherein said transmittance varying layer is made of a material whose transmittance changes at a predetermined temperature as a threshold value.
Claim 4
Dependent Claim 19 words
An optical disk according to claim 2, wherein said transmittance varying layer is made of a phase change material.
Claim 5
Dependent Claim 20 words
An optical disk according to claim 2, wherein said threshold value is within the temperature range from 700° to 500°.
Claim 6
Dependent Claim 23 words
An optical disk according to claim 3, wherein crystallization speed of said transmittance varying layer is equal to or slower than 500 ns.
Claim 7
Dependent Claim 29 words
An optical disk according to claim 1, wherein said transmittance varying layer is made of a material whose transmittance changes at a predetermined luminous intensity as a threshold value.
Claim 8
Dependent Claim 19 words
An optical disk according to claim 1, wherein said transmittance varying layer is made of an organic dye material.
Claim 9
Dependent Claim 29 words
An optical disk according to claim 1, comprising one or more additional recording layers between said first and second recording layers, each additional recording layer comprising a semi-transparent layer.

References Cited (Backward Citations)

US5604002A Cited
US5569517A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-10-05 2002-04-06 2002-10-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-10-05 2006-04-06 2006-10-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-10-05 2010-04-06 2010-10-06 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag